b'4. Brutons tyrosine kinase inhibitors: BTKi treatments aim to stop immune cells called B cells from attacking myelin by inhibiting a specic enzyme, a more targeted approach than other B cell-depleting treatments. (This class of treatment is still in the clinical phase trial, but is showing promising results). 5. Generics: Generic drugs are usually synthesized from chemicals and the manufacturing process results in an active ingredient that is the same within each manufactured lot and between lots. They are synthesized in a lab (whereas biosimilars are created utilizing living systems, such as animal cells, yeast, or bacteria). Source: Food & Drug AdministrationBTKi Research(Adapted from an article by Ellen Whipple, PharmD and Brittany Brooks, BS for MS Focus Magazine) BTK inhibitors are a new avenue of treatment for MS being researched. What is this potential treatment? How does it work? Lets examine what BTK is, so we can understand how these drugs that inhibit it might be helpful in MS.Brutons tyrosine kinase, or BTK, is an enzyme that plays a vital role in the immune response. It transmits signals that are critical for the activation of B cells. In a person with MS, some B cells can cross the blood-brain barrier and attack the protective myelin covering the nerves. BTK also plays a part in signaling other cells (myeloid cells, including macrophages and microglial cells), which leads to the secretion of pro-inammatory cytokines. Inhibiting BTK could block the activation of cell-signaling pathways related to the development of autoimmune diseases, such as MS.BTK inhibitors, the treatments being studied, are designed to selectively block this enzyme that is important for the activating B cells and microglia. B cells and cells of the myeloid lineage are important drivers in developing of multiple sclerosis, thus BTKi could provide therapeutic benets for MS. These drugs have been previously used in other areas of disease, such as graft versus host disease, lymphomas, and leukemia. One of the rst BTKis to be approved was ibrutinib. This rst-generation drug was approved in 2013 for lymphocytic leukemias and chronic GVHD. While it works well and has had signicant progress in affecting BTK, it also affects other kinases and B cell malignancies, leading to off-target activity and a signicant side-effect prole. This has led pharmaceutical researchers to look for alternatives with ibrutinibs efficacy but more specic targeting.There are two types of BTKis: irreversible inhibitors and reversible inhibitors. Irreversible inhibitors have a higher rate of inhibitory potency and selectivity than reversible inhibitors. For research in the treatment of MS, irreversible inhibitors have recently been at the forefront because of their potential advantages over biologic disease-modifying therapy options. These inhibitors can selectively target B-cells, wiping out those that harm the immune systems of people with MS while leaving normal B-cells alone. This shows an advantage over current B cell-depleting disease-modifying therapies, as they 10'